Fl_Timeout.h

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//
// Header for timeout support functions for the Fast Light Tool Kit (FLTK).
//
// Author: Albrecht Schlosser
// Copyright 2021-2022 by Bill Spitzak and others.
//
// This library is free software. Distribution and use rights are outlined in
// the file "COPYING" which should have been included with this file.  If this
// file is missing or damaged, see the license at:
//
//     https://www.fltk.org/COPYING.php
//
// Please see the following page on how to report bugs and issues:
//
//     https://www.fltk.org/bugs.php
//
 
#ifndef _src_Fl_Timeout_h_
#define _src_Fl_Timeout_h_
 
#include <FL/Fl.H>
 
#define FL_TIMEOUT_DEBUG 0        // 1 = include debugging features, 0 = no
 
class Fl_Timeout {
 
protected:
 
  Fl_Timeout *next;             // ** Link to next timeout
  Fl_Timeout_Handler callback;  // the user's callback
  void *data;                   // the user's callback data
  double time;                  // delay until timeout
  int skip;                     // skip "new" (inserted) timers (issue #450)
 
  // constructor
  Fl_Timeout() {
    next = 0;
    callback = 0;
    data = 0;
    time = 0;
    skip = 0;
  }
 
  // destructor
  ~Fl_Timeout() {}
 
  // get a new timer entry from the pool or allocate a new one
  static Fl_Timeout *get(double time, Fl_Timeout_Handler cb, void *data);
 
  // insert this timer into the active timer queue, sorted by expiration time
  void insert();
 
  // remove this timer from the active timer queue and
  // add it to the "current" timer stack
  void make_current();
 
  // remove this timer from the current timer stack and
  // add it to the list of free timers
  void release();
 
  double delay() {
    return time;
  }
 
  void delay(double t) {
    time = t;
  }
 
public:
  // Returns whether the given timeout is active.
  static int has_timeout(Fl_Timeout_Handler cb, void *data);
 
  // Add or remove timeouts
 
  static void add_timeout(double time, Fl_Timeout_Handler cb, void *data);
  static void repeat_timeout(double time, Fl_Timeout_Handler cb, void *data);
  static void remove_timeout(Fl_Timeout_Handler cb, void *data);
 
  // Elapse timeouts, i.e. calculate new delay time of all timers.
  // This does not call the timer callbacks.
  static void elapse_timeouts();
 
  // Elapse timeouts and call timer callbacks.
  static void do_timeouts();
 
  // Return the delay in seconds until the next timer expires.
  static double time_to_wait(double ttw);
 
#if FL_TIMEOUT_DEBUG
  // Write some statistics to stdout
  static void debug(int level = 1);
#endif
 
protected:
 
  static Fl_Timeout *current();
 
  static Fl_Timeout *first_timeout;
 
  static Fl_Timeout *free_timeout;
 
  static Fl_Timeout *current_timeout;   // list of "current" timeouts
 
}; // class Fl_Timeout
 
#endif // _src_Fl_Timeout_h_